This relates generally to graphics processing.
In graphics processors and real-time applications, a large portion of the computational resources and power budget is spent on executing pixel shading on the programmable cores of the graphics processors. For over twenty years, the prevailing method has been multisampling antialiasing (MSAA), where shading is invoked once per triangle and pixel. The cost of pixel shading is therefore tightly coupled to both the geometric complexity and the screen resolution, and it has been necessary to keep both low.
This is in contrast to the developers' goal of providing a richer visual environment. Tessellation is an advantageous means to reach that goal, as it can provide highly detailed geometry without having to store and transfer huge polygonal meshes. However, tessellation also drastically increases the cost of pixel shading, currently limiting its applicability to high-end devices.
There is also a trend towards very high resolution displays in consumer and professional devices, motivated by the reduction of distracting aliasing. This further increases the amount of shading work.